[PATCH 10/11] tpm: Add TPM2 support for write_lock

[Simon Glass]

Implement this API function for TPM2.

Signed-off-by: Simon Glass <s...@chromium.org>
---

 include/tpm-v2.h | 12 ++++++++++++
 lib/tpm-v2.c     | 23 +++++++++++++++++++++++
 lib/tpm_api.c    |  2 +-
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 6a400771af1..1ca1e7e2011 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -241,6 +241,7 @@ enum tpm2_command_codes {
        TPM2_CC_NV_DEFINE_SPACE = 0x012a,
        TPM2_CC_PCR_SETAUTHPOL  = 0x012C,
        TPM2_CC_NV_WRITE        = 0x0137,
+       TPM2_CC_NV_WRITELOCK    = 0x0138,
        TPM2_CC_DAM_RESET       = 0x0139,
        TPM2_CC_DAM_PARAMETERS  = 0x013A,
        TPM2_CC_NV_READ         = 0x014E,
@@ -570,4 +571,15 @@ u32 tpm2_pcr_setauthvalue(struct udevice *dev, const char 
*pw,
  */
 u32 tpm2_get_random(struct udevice *dev, void *data, u32 count);
 
+/**
+ * Lock data in the TPM
+ *
+ * Once locked the data cannot be written until after a reboot
+ *
+ * @dev                TPM device
+ * @index      Index of data to lock
+ * @return code of the operation
+ */
+u32 tpm2_write_lock(struct udevice *dev, u32 index);
+
 #endif /* __TPM_V2_H */
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index c0d1f3c5c7e..6bddafcc777 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -596,3 +596,26 @@ u32 tpm2_get_random(struct udevice *dev, void *data, u32 
count)
 
        return 0;
 }
+
+u32 tpm2_write_lock(struct udevice *dev, u32 index)
+{
+       u8 command_v2[COMMAND_BUFFER_SIZE] = {
+               /* header 10 bytes */
+               tpm_u16(TPM2_ST_SESSIONS),      /* TAG */
+               tpm_u32(10 + 8 + 13), /* Length */
+               tpm_u32(TPM2_CC_NV_WRITELOCK), /* Command code */
+
+               /* handles 8 bytes */
+               tpm_u32(TPM2_RH_PLATFORM),      /* Primary platform seed */
+               tpm_u32(HR_NV_INDEX + index),   /* Password authorisation */
+
+               /* session header 9 bytes */
+               tpm_u32(9),                     /* Header size */
+               tpm_u32(TPM2_RS_PW),            /* Password authorisation */
+               tpm_u16(0),                     /* nonce_size */
+               0,                              /* session_attrs */
+               tpm_u16(0),                     /* auth_size */
+       };
+
+       return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+}
diff --git a/lib/tpm_api.c b/lib/tpm_api.c
index 687fc8bc7ee..4c662640a92 100644
--- a/lib/tpm_api.c
+++ b/lib/tpm_api.c
@@ -144,7 +144,7 @@ u32 tpm_write_lock(struct udevice *dev, u32 index)
        if (is_tpm1(dev))
                return -ENOSYS;
        else if (is_tpm2(dev))
-               return -ENOSYS;
+               return tpm2_write_lock(dev, index);
        else
                return -ENOSYS;
 }
-- 
2.30.0.284.gd98b1dd5eaa7-goog